The present invention is a protective device for preventing unauthorized tampering with locking mechanisms and particularly is adopted for use with lock type door knobs to which access is generally easily possible by breakage of an adjacent window.
Various devices are known for providing protection for locking mechanisms. U.S. Pat. No. 3,660,996 describes a permanently attached, hinged cover for a door knob which can be secured by means of a key lock. The locking button of the door knob is accessible by means of a hole in the cover.
Another door handle cover is disclosed in U.S. Pat. No. 3,210,972. The cover comprises a five sided box which is attached by applying the box over the door knob, then inserting the sixth side and locking with a key lock.
U.S. Pat. No. 4,007,956 describes a permanent tube type cover which allows a key to be inserted in the door knob but includes construction to prevent the prying off of the knob itself from the shaft.
Another door knob protection device can be found in U.S. Pat. No. 2,458,002.
Automotive keyhole covers are described in U.S. Pat. Nos. 3,421,350, 3,782,149 and 3,861,182. These devices completely cover the keyhole and protect the mechanism within the door from water and ice. They may be attached by magnets in the cover itself. Another keyhole protection is offered in U.S. Pat. No. 4,073,165.
Even though considerable work has heretofore been undertaken in an effort to removably cover locks, a need exists for a cover which is completely removable, which need not be secured with a key lock and yet which effectively discourages tampering with the enclosed locking mechanism. An object of this invention is to provide a device utilizing such a cover.